Neither stupid time-slot changes nor grotesque TV biopics can stop the juggernaut that is ROSEANNE (ABC, Wednesdays, 9-9:30 p.m.). Now in its seventh season, Roseanne remains endlessly watchable: startling, funny, and complicated. Even more amazing, the star of the show has maintained this accomplishment while going through a nasty public divorce; submitting to cosmetic surgery that has her looking somehow slightly altered every time you tune in; and withstanding the stunning mediocrity of Fox’s Roseanne: An Unauthorized Biography and NBC’s Roseanne & Tom: Behind the Scenes. (If you ever wanted to know why networks indulge stars and pay them exorbitantly, all you had to do was watch would-be-Roseannimators Denny Dillon and Patrika Darbo trying to get laughs doing the then-Roseanne Barr’s early-period surefire stand-up-comedy act: no laughs, not once.)

Last season, Roseanne’s overriding theme, week in, week out, was money: getting jobs and losing them, starting businesses and folding them, scrimping to keep the kids in college and put food on the table. Here was a post- Reaganite economic critique with belly laughs — trickle-down sitcommery. This season, in a Clinton-era development that seems somehow logical, the subject that pervades nearly every Roseanne story line is sex. In one episode after another, questions are asked and answered: Is Roseanne pregnant? Is daughter Darlene (Sara Gilbert) doing it with boyfriend David (Johnny Galecki)? Is the sex life of Jackie (Laurie Metcalf) and Fred (Michael O’Keefe) suffering since the birth of their child? Is Fred secretly gay? Did David have a sexy dream about his girlfriend’s sister, Becky (Sarah Chalke), or, more confoundingly, did he actually have one about Roseanne? Why, Roseanne even found room in a recent episode for ex-porn star Traci Lords to test out her acting lessons.

Over the past few months, Roseanne has featured more risqué — oh, hell, dirty — jokes than I’ve ever heard on network television; even better, they’ve been really good dirty jokes. And at a time when TV movies are loath to present any sexual minority in a poor light, Roseanne is the sitcom proud to make everyone look bad at one time or another. When Sandra Bernhard, overstaying her welcome as Roseanne’s openly gay pal Nancy, recently sneered, ”I can’t believe the breeders are trying to take back Halloween,” this breeder was pleased at how freely I was permitted to dislike Nancy without feeling a twinge of guilt. That’s because the show makes it clear that it’s Nancy’s personality, not her sexuality, that makes her comically insufferable.

Ample proof of Roseanne’s uniqueness and endurance sits on either side of her on ABC’s Wednesday-night lineup. At 8:30, Margaret Cho is attempting an Asian Valley Girl version of Roseanne on All-American Girl, and the results are eye-averting. At 9:30, the anemic Ellen is going Seinfeld one better — Ellen is not only about nothing, it also features nobody: Ellen DeGeneres’ no-stick costars exhibit scant personality other than a barely disguised obsequiousness as Ellen gets all the good lines.

By contrast, the supposedly egomaniacal Roseanne, working with a by-now fairly stable stable of writers and directors, regularly hands off the choicest moments of her show, week after week, to her supporting cast. This season, the boy roles have been enlarged, with Galecki, O’Keefe, and Glenn Quinn’s Mark becoming essential elements in the family ensemble. It would be understandable if an actor as good as John Goodman were bored with his character at this point in the series’ run, but Goodman’s exuberant physical comedy in recent episodes has made him seem all the more enthusiastic.

Other shows regularly surge ahead of it in the ratings these days — Grace Under Fire does it by offering a shrewd variation on Roseanne’s white-trash ethos — but Roseanne remains a solid top five achiever while featuring a performer who, by this time, should have burned out on media overexposure. Of living stars, only Michael Jackson and Madonna can approach Roseanne as the pop entertainer whose life most regularly supersedes her art. But while Jackson and Madonna have the luxury of calling their own artistic shots, of releasing new work only when they deign to do so, Roseanne cranks out great stuff week after week, working under the rules and constraints of commercial television.

Chances are good that with its early years now in syndication, Roseanne is coming down its creative homestretch, so don’t decide to get tired of the show now. More and more, for all its roughness and vulgarity, Roseanne looks like a serenely blessed pop-culture miracle. A